The redox states of serum and synovial fluid of patients with temporomandibular joint disorders

The redox states of albumin in serum and synovial fluid (SF) were analyzed in 35 female patients with temporomandibular joint disorders and 9 asymptomatic female healthy volunteers by high-performance liquid chromatographic (HPLC) analysis. Human serum albumin (HSA) is divided by HPLC analysis into three fractions: mercaptalbumin (HMA, reduced form) and nonmercaptalbumin (HNA-1 and HNA-2, oxidized forms). It was found that the characterized values of albumin in SF of patients with the disorders were the fraction of HMA (f (HMA), 65.8+/-9.1%), the fraction of HNA-1 (f (HNA-1), 31.3+/-8.8%), and the fraction of HNA-2 (f (HNA-2), 2.9+/-0.9%), respectively, and similarly the values of albumin in serum of same subjects were f (HMA), 79.4+/-4.0%; f (HNA-1), 18.7+/-3.8%; and f (HNA-2), 1.9+/-0.5%. The HNA fractions in SF were significantly higher than those in serum (p<0.0001). The SF of patients and even control showed more oxidative condition compared with sera of the same subjects. Each fraction of SF showed significant difference in control (p<0.05), and greater significance in patients (p<0.0001). Furthermore, the HNA-2 fraction (f (HNA-2), 2.9+/-0.9%) in SF of the patients with temporomandibular joint disorders revealed a significantly higher value (p<0.01) than that (f (HNA-2), 1.7+/-0.3%) of controls. These findings suggested that SF of the temporomandibular joint is more locally oxidized than serum; thus oxidative factors are concerned in the pathogenesis of the temporomandibular joint disorders. It was also suggested that synovial albumin may play a scavenging role against the intraarticular oxidative stress.